only with its last 500 years (4500-4000 BC). Only at Newferry is there a chronological sequence which spans the known Later Mesolithic and except for zone 3, for which there are contemporary sites, there are no comparable assemblages for the remainder of the material. If all the contexted material relates to the final phases of a period which lasted for at least 2,000 years, then with the exception of a very few sites, none of which contain all the elements of a lithic assemblage, there is a possibility that the material representative of the first 1,500 years is missing. Thus, it is fair to say that much of the Later Mesolithic (c. 7-6000 - 4000 BC) is impressively underrepresented. Ironically, it is with the last part of the Later Mesolithic that some workers have become most frustrated, like Whittle, who was stymied by his research into Ireland's transition to the Neolithic: Much further research is needed, and the outlook is unfortunately gloomy. Key sites of the right date will be hard to locate in river valleys and estuaries, and the funding of problem-oriented research is not easy. We may have to wait patiently for chance discoveries of the appropriate kind. In truth, this pessimism might be better directed at the first three quarters of the Later Mesolithic, rather than the last quarter. The difference is not only in the availability of evidence, but also in the availability of new data arising from the evidence with the application of stable isotope analysis. Indeed, stable isotope analyses, in combination with the advantages of AMS dating, are cutting through the gloom and revealing glimpses of a surprisingly dynamic sixth millennium BP forager lifeway. Later Mesolithic Mobility & Economy The limited evidence for the Later Mesolithic from excavated sites and stray finds suggest a residential mobility strategy consisting of short-term food and raw material procurement and processing camps oriented toward coasts, estuaries, rivers and lakes. No inland, terrestrially-oriented sites have yet been identified. Regional surveys including the Lough Swilly Archaeological Survey in eastern County Donegal, the Bally Lough Archaeological Project in County Waterford and the broader Barrow Valley Archaeological Survey in southeast Ireland have confirmed this pattern. Excavations at the floodplain site of Newferry in County Antrim, the coastal, industrial site of Bay Farm, also in County Antrim, and the coastal sites of Ferriter's Cove in County Kerry and Belderrig highlight the small-scale, short-term